General Chemistry Question?!?!?

[farvabull]

Hey guys, i'm having trouble w/ this question, it's impossible!!! If u could help me out, or atleast explain how to do it i'd really appreciate it. THX

"Vinegar is a dilute aqueous solution of acetic acid. Acetic acid reacts w/ sodium hydroxide according to the following equation:
CH3COOH (acetic acid) + NaOH yields H20 + CH3COONa (vinegar)

If 2.50 mL of vinegar requires 34.9 mL of 0.0960M NaOH to reach the equivalence point in a titration, how many grams of acetic acid are in a 1L sample of vinegar?

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[mercaptovizadeh]

Hey guys, i'm having trouble w/ this question, it's impossible!!! If u could help me out, or atleast explain how to do it i'd really appreciate it. THX

"Vinegar is a dilute aqueous solution of acetic acid. Acetic acid reacts w/ sodium hydroxide according to the following equation:
CH3COOH (acetic acid) + NaOH yields H20 + CH3COONa (vinegar)

If 2.50 mL of vinegar requires 34.9 mL of 0.0960M NaOH to reach the equivalence point in a titration, how many grams of acetic acid are in a 1L sample of vinegar?

The equivalence point is at complete neutralization:

[vinegar]*volume(vinegar) = [NaOH]*volume(NaOH) at equivalence.

So, [vinegar] = 0.096*34.9/2.5 = 1.34016 M.

Molar is just moles/L, so, in 1 L of vinegar, there are 1.34016 moles of acetic acid.

Molar mass of acetic acid: 60.0524 g/mol

So, there is a total of 60.0524*1.34016 = 80.4798 g acetic acid.

Or, in "sig figs," 80.5 g

 

[farvabull]

The equivalence point is at complete neutralization:

[vinegar]*volume(vinegar) = [NaOH]*volume(NaOH) at equivalence.

So, [vinegar] = 0.096*34.9/2.5 = 1.34016 M.

Molar is just moles/L, so, in 1 L of vinegar, there are 1.34016 moles of acetic acid.

Molar mass of acetic acid: 60.0524 g/mol

So, there is a total of 60.0524*1.34016 = 80.4798 g acetic acid.

Or, in "sig figs," 80.5 g

thanks alot!!!

 

[texasaggie2005]

thanks alot...but don't u have to convert the mL to L to obtain an accurate molar value...or am i just being an idiot?

The units cancel, both volume measurements are in mL.

 

[farvabull]

thanks a ton, i'm just blanking tonight

I have another one for you...although u can just hint me to what i should do, cuz i feel bad just asking for the answers...thx

"What mass of NaCl is required to precipitate all the silver ions from 20.0 mL of .100 M AgNo3 solution?"

 

[MikePhen2]

I just wanted to say for the record that I hate equilibrium chemisty. Nonetheless, I have to take Analytical Chem this summer because I go to one of the only schools in the world that requires it as a prereq for biochem. Damn this summer is going to suck !

 

[texasaggie2005]

thanks a ton, i'm just blanking tonight

I have another one for you...although u can just hint me to what i should do, cuz i feel bad just asking for the answers...thx

"What mass of NaCl is required to precipitate all the silver ions from 20.0 mL of .100 M AgNo3 solution?"

I think silver chloride is pretty much insoluble. So you would need an equivalent number of Cl- ions to Ag+ ions.

(20.0 mL)(0.100 M) = 2.00 mmol

(2.00 mmol)(58.45 g/mol) = 0.117 g

I think. Quant was a LONG time ago.

EDIT: fixed atomic weight

 

[farvabull]

I think silver chloride is pretty much insoluble. So you would need an equivalent number of Cl- ions to Ag+ ions.

(20.0 mL)(0.100 M) = 2.00 mmol

(2.00 mmol)(58.45 g/mol) = 0.117 g

I think. Quant was a LONG time ago.

EDIT: fixed atomic weight

thanks, u made my night alot easier